Objective: Hydrogen sulfide, a well-known toxic gas with the smell of rotten eggs, was proved to be generated in vivo in human and animal organisms and participated in many pathophysiological processes. Hypertension is one of the most common diseases harmed seriously, while the mechanisms are far from clear. Proliferation of aortic smooth muscle cells (ASMCs) is a pivot component of the development of hypertension.: To investigate the effect of hydrogen sulfide on the proliferation of ASMCs of normal rats and spontaneous hypertensive rats (SHRs). Methods: ASMCs of normal rats and spontaneous hypertensive rats were cultured and separated into experimental group and control group, respectively. The experimental group was added into NaHS (hydrogen sulfide donor) or PPG (the inhibitor of hydrogen sulfide synthesis) of different consistencies, while the control group was added into DMSO of equal volume. PCNA and p-ERK in ASMCs were detected by Western blot at each time point. Results: NaHS had no effect on the proliferation of ASMCs of normal rats and the expression of p-ERK. PPG advanced the proliferation of ASMCs of normal rats and the expression of p-ERK obviously. NaHS inhibited the proliferation of ASMCs of SHR and the expression of p-ERK obviously. PPG advanced the proliferation of ASMCs of SHR and the expression of p-ERK obviously. Conclusion: hydrogen sulfide could regulate the proliferation of ASMCs of normal rats and SHR through inhibiting the expression of p-ERK.